I decided to reinstall Windows 10 using the menus that come up when you press Shift and Restart Windows. I chose the option that kept my files too.
Once I did that I plugged my 2 sensors into two USB 3 ports on my motherboard on the same Hub and connected my Rift to a USB port on my motherboard (with my USB Mouse and Keyboard on the same Hub.
I had to try several times for the Oculus app to see both of my sensors with a strong enough signal and once I went through the full setup (Rift and Touch controllers) I found that my height was correct and my Guardian boundaries (so far at least!) have stayed where they should be!
It’s a bit of a pain in the arse because I had to reinstall EVERYTHING (apart from my games which were on a seperate drive to my system drive) including my internet security and antivirus, Stremio, VLC Media Player etc but it was worth it. Going to reinstall Unity and Unreal at some point too but I can’t be bothered at the moment!
Just thought I’d give you guys a heads up in case doing the same thing works for you! It’s a bit drastic but it worked!!!:oD